Improved tall grass using the new generic random map.

I tweaked the hue of the two grass textures used to make it a bit more bluegrass in color.

The basic spacing is still the same, at one grass plant every 5 feet (5 d3d units).

The grass plant meshes are unchanged: 8 quads, 4 in the center tilted out, and 4 tilted way out very near to the ground.

Everything else is controlled by the new "generic random map" in the game. I found a repeating need for 2d arrays of random values for things like what ground texture tile to draw, what scale a plant should be, etc. So i created a "generic random map", a 100x100 2d array of random integer values from 0 through 100. this map is generated once at game start. Functions / methods are then written that access the random map to return values. For example, the x,z location of a grass plant is modded by 100 to map to the 2d 100x100 array and return a value 0-100. this is then multiplied by a scaling factor (such as 0.02f) and then added to a base scaling value (such as 1.5f) to determine the final size of the plant at that location.